1. Field of the Invention
The invention relates to an electric vehicle, and more specifically to an electric vehicle having a configuration capable of supplying electric power to external equipment that is not a component of the electric vehicle, by using electric power of a vehicle-mounted electric power storage device.
2. Description of Related Art
In an electric vehicle such as an electric car, a hybrid car, or a fuel cell car configured to be capable of generating a vehicle driving force using a motor, an electric power storage device that stores electric power for driving the motor is mounted.
With regard to a hybrid car as one aspect of the electric vehicle in which an engine and a motor are mounted, Japanese Patent Application Publication No. 2008-162543 (JP-2008-162543 A) describes a hybrid car capable of supplying stored electric power of an electric power storage device to the outside of the vehicle. In addition, Japanese Patent Application Publication No. 2011-93491 (JP-2011-93491 A) describes a hybrid car capable of supplying electric power to external equipment from a battery by connecting the external equipment to a receptacle connected to the battery.
In the hybrid car described in JP-2011-93491 A, in a case where the state of charge (SOC) of the battery is lowered when electric power is supplied to the external equipment from the vehicle-mounted battery, an engine is started in order to charge the battery. At this point, by displaying an arrow indicative of the flow of the electric power between the battery and the receptacle, the start of the engine that a driver does not expect is prevented.
Japanese Patent Application Publication No. 2010-187466 (JP-2010-187466 A) describes a configuration of a vehicular battery charger capable of exchanging electric power between electric cars only by connecting a cable to the electric cars. In addition, Japanese Patent Application Publication No. 2004-357459 (JP-2004-357459 A) describes that, in order to prevent overcharging or overdischarging of the battery in the hybrid car, the allowable range of a motor output is set based on an input/output electric power restriction of the battery according to the state of the battery.
As described in JP-2011-93491 A, even while the electric power is supplied to the external equipment that is not the component of the vehicle, a low state of charge of the battery triggers the start of execution of control, in which electric power for charging the electric power storage device (the battery) is generated by other power sources represented by the engine.
As a result, in a case where the SOC is not properly managed when the electric power is supplied to the external equipment, a state where the SOC is low continues and there is a fear that forced charging of the electric power storage device involving engine operation is frequently executed. When the number of times of the engine operation is increased, it is feared that fuel efficiency deteriorates.